Shower header-type liquid spraying systems are used in a variety of different industrial applications typically to direct fluid onto some sort of processing line, e.g., directing cleaning fluids onto rollers in pulp and paper mills and spraying cooling fluids onto processed metals in steel mills. Such spraying systems typically include a plurality of shower spray nozzle assemblies mounted in laterally spaced relation along a header so as to be able to direct a curtain of liquid onto the processing line. Since a single processing line can include a number of such shower headers, such spray systems use a substantial volume of cleaning, cooling or other processing fluids. As a result, to conserve processing fluid, it is common to collect the fluid discharge, filter out the debris and contaminants from the fluid during a recycling process, and reuse the liquid. Despite the filter system, some particulates and other matter can pass back into the headers. Over time, this can plug or impede liquid flow through the spray nozzles on the header.
To help clean out the spray nozzles, the shower headers can include an elongated brush assembly that can be rotated within the header in order to dislodge any debris from the shower spray nozzle assemblies. The brush assembly typically includes an elongated brush rod on which a plurality of brushes are arranged. The brushes are arranged at regular staggered intervals on the brush rod to provide maximum coverage of the interior of the shower header while minimizing the impediment to the flow of fluid through the shower header caused by the brushes.
From time to time, it becomes necessary to remove and replace the brushes and/or the brush rod due, for example, to excessive wear. Unfortunately, this can be very difficult to accomplish in the field. For instance, to ensure proper operation, the brush rod and brushes must be positioned and aligned precisely in the shower header. If the brush rod or brushes are off-center, the brushes can interfere excessively with the inside wall of the header hindering or even preventing rotation of the brush assembly. However, because the brush rod can be quite long, with lengths of forty feet or more not being uncommon, it can be very difficult to properly center the brush rod, and thus the brushes, in the shower header in the field where there are not any special fixtures to assist with the alignment process. As will be appreciated, providing special fixtures for each field replacement of a brush rod is simply not practical and in any event would be very expensive. Another problem with field replacement of the brush rod is that the length of the rod makes it difficult and expensive to ship.
Field replacement of just the brushes can also be difficult. The brushes are typically secured to the brush rod via welding. Again, to ensure that the brushes operate properly, they must be positioned precisely with respect to the axial centerline of the brush rod. When the shower header and brush assembly are initially fabricated in a plant, special fixtures are typically used to ensure the proper alignment of the brushes. However, as with the special fixtures for locating the brush rod, it is not practical to use the brush locating special fixtures for each field replacement of a brush.